Pairwise selectivity of guests in an encapsulation complex creates a potentially general and powerful tool for molecular recognition. When two different guests are held within the interior of a host, the association constant of one guest depends strongly on the structure of the other. The affinity and selectivity for a particular guest within a given host, therefore, can be tuned through the choice of an appropriate co-guest. This project investigates the encapsulation of guest pairs in a reversibly-formed host assembly with the ultimate goal of applying pairwise encapsulation to chiral molecular recognition and the catalysis of [3,3]-sigmatropic rearrangements.